compose [nfc]: Remove narrow from _ComposeBoxBody

Author: PIG208

lib/widgets/compose_box.dart

@@ -1405,9 +1405,6 @@ class _ComposeBoxContainer extends StatelessWidget {
 
 /// The text inputs, compose-button row, and send button for the compose box.
 abstract class _ComposeBoxBody extends StatelessWidget {
-  /// The narrow on view in the message list.
-  Narrow get narrow;
-
   ComposeBoxController get controller;
 
   Widget? buildTopicInput();
@@ -1478,7 +1475,6 @@ abstract class _ComposeBoxBody extends StatelessWidget {
 class _StreamComposeBoxBody extends _ComposeBoxBody {
   _StreamComposeBoxBody({required this.narrow, required this.controller});
 
-  @override
   final ChannelNarrow narrow;
 
   @override
@@ -1506,7 +1502,6 @@ class _StreamComposeBoxBody extends _ComposeBoxBody {
 class _FixedDestinationComposeBoxBody extends _ComposeBoxBody {
   _FixedDestinationComposeBoxBody({required this.narrow, required this.controller});
 
-  @override
   final SendableNarrow narrow;
 
   @override
@@ -1531,7 +1526,6 @@ class _FixedDestinationComposeBoxBody extends _ComposeBoxBody {
 class _EditMessageComposeBoxBody extends _ComposeBoxBody {
   _EditMessageComposeBoxBody({required this.narrow, required this.controller});
 
-  @override
   final Narrow narrow;
 
   @override